$ { \left[\begin{array}{rrr}{1} & {-1} & {1} \\ {0} & {2} & {-2}\end{array}\right]-\left[\begin{array}{rrr}{3} & {1} & {3} \\ {0} & {4} & {1}\end{array}\right] = {?} } $
Explanation: To find the difference of two matrices, subtract the corresponding items between each matrix. ${\left[\begin{array}{rrr}{1}-{3} & {-1}-{1} & {1}-{3} \\ {0}-{0} & {2}-{4} & {-2}-{1}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rrr}{-2} & {-2} & {-2} \\ {0} & {-2} & {-3}\end{array}\right]}$